Question
If 12 is added to each term of the AP : -12,-9,-6,...,21 then
which of the following is true about the sum of all terms of the AP thus obtained ?
A) The sum will increase by 12
B) The sum will increase by 144
C) The sum will become 12 times
D) The sum will become 144 times
which of the following is true about the sum of all terms of the AP thus obtained ?
A) The sum will increase by 12
B) The sum will increase by 144
C) The sum will become 12 times
D) The sum will become 144 times
Answers
oobleck
There are (21+12)/3 + 1 = 12 terms
so the sum will increase by 12*12 = 144
so the sum will increase by 12*12 = 144